The invention generally relates to a medical forceps comprising two independently moveable jaw parts at a distal end of a shaft in which two rods extend axially, which are arranged adjacent to one another and are axially displaceable independent of one another. The first rod is joined to the first jaw part and the second rod is joined to the second jaw part. A handle is provided on the proximal end having two actuator elements, where the first actuator element is joined to the first rod and the second actuator element is joined to the second rod.
Forceps of this type are disclosed in U.S. Pat. No. 5,403,332 or in U.S. Pat. No. 5,171,257. Forceps of the above-mentioned type are normally used in endoscopic surgery as multifunctional instruments, for example to cut tissue with the first jaw part and to grasp the tissue with the other jaw part for removal of the tissue from the body. Accordingly, the first jaw part is formed as a cutting tool, while the other jaw part is configured as a grasping tool. Both jaw parts are moveable independent of one another, i.e. they can be independently opened and closed. For this purpose, the forceps comprise an actuator element for each jaw part, with which the corresponding jaw part can be opened or closed.
Two rods arranged axially adjacent to one another are provided in the shaft for transmitting force from the actuator elements to the jaw parts. The first rod at its proximal end is coupled to the first actuator element and at its distal end to the first jaw part and the second rod is coupled at its proximal end to the second actuator element and at its distal end to the second jaw part in force-locking manner. The two rods operate to close and open the jaw parts in response to tension or pressure.
A disadvantage of the known forceps is that neither the rods nor the shaft can be removed from the handle, whereby the forceps are not accessible to thorough cleaning or only accessible with difficulty. However, when using such forceps in a surgical operation, impurities collect between the shaft and the rods. A flushing opening is provided between the handle and the shaft in the known forceps, through which flushing fluid can be introduced into the shaft for cleaning the shaft interior. However, a thorough cleaning of the shaft interior and the rods extending therein is not guaranteed by introducing a cleaning fluid, because for example pieces of tissue having entered the shaft can remain adhered to the adjacent rods or on edges or in recesses, which cannot be removed by the cleaning fluid.
The object of the invention is therefore to provide an improved medical forceps of the mentioned type, in which the forceps can be disassembled for cleaning, where the rods are removable from the handle and where- the forceps after cleaning should be rapidly available for repeated use and should be easy to reassemble.
According to the present invention, a medical forceps is provided, comprising:
a shaft having a distal end and a proximal end;
a first and a second jaw part disposed at said distal end of said shaft and being movable independently from each other;
a handle disposed at said proximal end of said shaft having a first and a second actuator element;
a first and a second rod extending through said shaft and being arranged adjacent to one another and being axially displaceable independently from one another, said first rod being joined to said first jaw part and to said first actuator element and said second rod being joined to said second jaw part and to said second actuator element,
wherein said first rod and said second rod each comprise a coupling element at a proximal end of said first and second rod, said first actuator element and said second actuator element each comprise a coupling element at a distal end of said first and second actuator element, said coupling elements of said actuator element being substantially complementary to said coupling elements of said rods such that said coupling elements of said rods are engageable in force-locking, but releasable manner with said coupling elements of said actuator elements by axially pushing said rods and said actuator elements together and/or by commonly rotating said rods about a longitudinal axis of said shaft.
The medical forceps according to the present invention thus provide that the rods are configured to be removable from the handle, for which purpose the proximal ends of the rods and the distal ends of the actuator elements comprise coupling elements which are substantially complementary to one another and are releasable from one another. The coupling mechanism of the forceps according to the invention has a constructively simple configuration and allows a simple manual operation, because the connection of the rods with the actuator elements is accomplished with simple manipulations, namely by pushing the rods together and/or by rotating the rods.
This coupling mechanism is also advantageous because no securement means are needed to couple the rods with the actuator elements, for example screws, so that no tools such as a screwdriver is necessary to assemble the forceps for renewed use. Axially pushing and/or rotating are very simple manipulations.
The present medical forceps can be thoroughly cleaned after removing the rods, because the removed and therefore accessible rods can be separately washed, so that impurities or contamination collected in intermediate spaces between the rods or at the edges can be reliably removed.
The coupling elements can be complementary round structures, for example spherical or ball-joint structures. The structures may also not be round, for example wedge-shaped structures having counterengaging sections so that tension and compression forces from the actuator elements are transmitted to the rods. The rods themselves can have any suitable cross sectional shape, for example round or not round, for example rectangular.
In a preferred embodiment of the forceps according to the present invention, the coupling elements of the rods and the coupling elements of the actuator elements are configured such that they are disengageable by a rotation of the rods about the mentioned longitudinal axis.
This has the further advantage that the rods can be released in simple manner without the necessity of using tools or the like. The further advantage of the coupling mechanism, releasable by rotating the rods, is the particularly simple constructive design of the present forceps.
In a further preferred embodiment, the coupling elements of the rods become lockingly engaged with the coupling elements of the actuator elements by actuating the actuator elements and/or by actuating the jaw parts.
An advantage here is that the force-locking connection of the rods and the actuator elements is accomplished by actuating the actuator elements through grips normally provided on the handle, which are connected with the actuator elements, whereby the connection of the actuator elements with the rods is accomplished in particularly simple and reliable manner. The actuator elements can be displaced relative to the rods by actuating the actuator elements, where the rods connected to the jaw parts can be displaced relative to the actuator elements by actuating the jaw parts.
In a further preferred embodiment, the coupling elements of the rods and/or the coupling elements of the actuator elements comprise engagement slopes.
This has the advantage that the coupling elements of the rods and the coupling elements of the actuator elements are forcibly guided when axially pushed together, by which the coupling elements of the rods self-engage with the coupling elements of the actuator elements when pushed together, without having to first actuate a catch or the like.
It is preferred in this context that the rods are slightly elastically bendable at their proximal end.
This has the advantage that the rods in this configuration are sufficiently bendable on the one hand so that the coupling elements can glide along the engagement slopes without increased frictional resistance, where the proximal ends of the rods are deflected from their longitudinal axis. On the other hand, the coupling elements of the rods after overcoming the engagement slopes then engage elastically and lockingly with the coupling elements of the actuator elements and establish a force-locking connection between the rods and the actuator elements.
In a further preferred embodiment, the rods are restricted against undesired rotation when the coupling elements of the rods are engaged with the coupling elements of the actuator elements.
This feature is of advantage, especially with the above-mentioned embodiment where the coupling elements of the rods are disengageable from the coupling elements of the actuator elements by rotating the rods about the longitudinal axis, because this prevents the rods from being released from the actuator elements during use of the forceps in a surgical operation, whereby the operational safety of the forceps is improved.
In a further preferred embodiment, the shaft is releasably joined to the handle.
This feature provides the further advantage that not only the rods are removable from the handle and therefore can be cleaned separately, but also the shaft can be removed so that it can also be thoroughly cleaned, particularly its interior.
Preferably the shaft is joined to the handle by means of a locking mechanism arranged on the handle.
This has the advantage that the shaft is also connectable and removable from the handle in a simple manner, where the locking mechanism guarantees a reliable interconnection between the handle and the shaft during use of the forceps.
In a further preferred embodiment, the locking mechanism secures the shaft against rotation.
This feature has the further advantage that the shaft is secured against rotation without further constructive means as soon as the shaft is locked on the handle, whereby further parts for securing against rotation are saved.
In a further preferred embodiment, the shaft is removable from the rods and the rods are secured against rotation with the shaft in the assembled condition.
This feature has the advantage that the forceps according to the invention can be further disassembled, so that the cleaning capabilities of the present forceps are further improved. The further advantage of this feature is that the rods are already secured against rotation by the shaft, with which they are joined in assembled condition, so that further means for securement against rotation of the rods is not necessary, which reduces the complication of the structure of the present forceps.
In a further preferred embodiment, the coupling elements of the rods are formed as heads and the coupling elements of the actuator elements are formed as bore holes substantially complementary thereto, which are open at a distal front face of the actuator elements and open to the side, or vice versa.
This feature allows a constructively very simple configuration of the coupling elements of the rods as well as the coupling elements of the actuator elements, which in the connected condition also guarantees a mechanically reliable closed linkage between the rods and the actuator elements. The heads are preferably provided as balls and the bore holes formed as ball sockets. Clearly it is also possible to provide the heads on the actuator elements and the bore holes on the rods.
Preferably, the side opening of the first ball socket-faces in the opposite direction with respect to the side opening of the second ball socket.
This feature is of advantage, in particular in conjunction with the mentioned coupling mechanism, where the coupling elements of the rods are engaged and disengaged with the coupling elements of the actuator elements by rotating the rods about the longitudinal axis. This configuration however also makes it possible to engage the coupling elements of the rods with the coupling elements of the actuator elements by axially pushing the elements together.
Further advantages will become apparent from the following description and the appendant drawing. It will be understood that the above-mentioned features and those to be discussed below are not only applicable in the given combinations, but may also be employed in other combinations or taken alone without departing from the scope of the present invention.
An embodiment of the invention is illustrated in the drawings and will be discussed in the following with reference to the figures.